During the early 1990s, James P. Allison studied a T cell protein called CTLA-4. The protein acts as a brake on the action of T cells, ensuring that these cells do not attack healthy tissue and by 1994, he and his colleagues had shown that blocking CTLA-4 was an effective cancer therapy in mice. A few years before Allison’s discovery Tasuku Honjo and his team working at Kyoto University in Japan discovered the T cell protein PD-1. Honjo experimented with a PD-1 blocking antibody which rendered the T cells freely able to detect and destroy cancer cells. A little over 10 years later in 2018 Honjo & Allison would share the Nobel Prize for Medicine in recognition of their work as the genesis of Immune Checkpoint Therapy.

A Texas native, James P. Allison was inspired in 8th grade to study biology. In 1969 Allison graduated from the University of Texas Austin and earned his PhD in 1973. After his PhD, Allison joined the Scripps Clinic and Research Foundation as a postdoctoral fellow until 1984 when he would be appointed a Professor of Immunology and director of the Cancer Research Library at the University of California Berkeley, where he would, in the 1994 develop CTLA-4 blockade.

Since the initial studies showing the effects of CTLA-4 and PD-1 blockade, the clinical development has been dramatic. Immune checkpoint therapy has now fundamentally changed the outcome for certain groups of patients with advanced cancer. Of the two treatment strategies, checkpoint therapy against PD-1 has proven more effective in several types of cancer. However, new clinical studies indicate that combination therapy, targeting both CTLA-4 and PD-1, can be even more effective. Thanks to the seminal discoveries by the two laureates checkpoint therapy has now revolutionized cancer treatment and has fundamentally changed our view on how cancer can be managed.